The above-referenced invention relates to vehicle heating, ventilation and air-conditioning systems, and more specifically to an air distribution module for directing air-flow to different portions of the vehicle interior.
Vehicle ventilation systems have long been utilized in vehicles to provide comfort to the vehicle occupants. Initial ventilation systems comprised a simple duct that was opened or closed by a manually operated valve directing outside ambient air to the vehicle interior. Through the years, consumers have desired increased interior comfort and manufacturers have delivered systems to satisfy consumer demand for improved interior temperature control. Advances made over the years include directing air through a heated core for delivering hot air to the vehicle interior and also for delivering hot air to the windshield to keep the windshield clear of frost and moisture. Subsequently, air conditioners have also become commonplace accessories in vehicles to provide cool air for the comfort of passengers in summer""s heat.
Heating, ventilation, and air-conditioning systems in today""s vehicles now provide total interior climate control. These new systems automatically maintain a desired temperature by delivering an appropriate mix of ambient, cooled, and heated air to the vehicle interior. More advanced systems also permit occupants to select a desired temperature for their individual zones and automatically maintain these zones at the pre-selected temperature. Such operation necessarily requires the automatic operation of the vehicle HVAC system wherein the ambient, cooled, and heated air are directed into an air distribution module to be ducted to the desired areas of the vehicle.
A prior art HVAC system is shown generally at 10 in FIG. 1. The vehicle HVAC system 10 is comprised of core module 12 and air distribution module 30. Ambient outside air or recirculated interior air is directed to air inlet 14 and is subsequently directed through air-conditioning evaporator 16 by the HVAC blower (not shown). After the air exits from evaporator 16 to pass between point 19 and wall 20, part of the air is directed through cool inlet area 22 and part of the air is directed to warm air passage 24. Inlet 22 and passage 24 are variable in area depending upon the position of air mix door 18. Air mix door 18 is hinged at 17 to pivot therearound and the position of air mix door 18 is directly related to the desired air temperature of air to be output to the interior of the vehicle. Thus, to obtain the maximum amount of cool air, air mix door 18 is rotated counterclockwise to maximize the area of cool air inlet 22. If heated air is desired, air mix door 18 is rotated clockwise to create a warm air passage 24 thereby diverting a portion of the air-flow exiting from evaporator 16 to flow through heater core 26 and duct the heated air through heated air inlet 28. An intermediate position of air mix door 18 facilitates a mixture of cool and hot air simultaneously entering air chamber 32 of air distribution module 30 to provide air at a desired temperature.
Air distribution module 30 typically has three designated outlets for delivering the conditioned air to different portions of the vehicle. These outlets are generally referred to as a defrost outlet 36 for delivering air to the interior surface of the windshield, vent outlet 40 for delivering air to the upper portion of the vehicle interior, and a heater outlet 44 for delivering air to the foot wells of the vehicle interior. Valves 34, 38, and 42 are selectively positionable in closed, opened, or intermediate positions to place the desired HVAC in the desired function. The HVAC system 10 is typically located in the center of the vehicle as are outlets 36, 40, and 44. Although there may be some mixing of the air upon entry to air distribution module 30, it is readily apparent that the cool or ambient air is directed to the upper portion of module 30 and the heated air is directed to the lower part of module 30 thereby creating a layered air-flow wherein the upper air layer is typically cooler than the bottom air layer.
Thus, the top-centered defrost outlet 36 is prone to discharging air that is substantially cooler than the air discharged through heater outlet 44 when air mix door 18 is in an intermediate position. Another disadvantage of the above-described HVAC system is that the bottom-center heater air outlet 44 is too low and rearward on the vehicle, and often requires complicated ducts to deliver the heated air to a desired location in the vehicle foot well. The top-center defrost air outlet 36 concentrates defroster air-flow at the center of the windshield which will in turn clear the center of the windshield before clearing the windshield area in the driver""s and the passenger""s line of sight. This undesirable situation is typically resolved by the incorporation of complex and relatively expensive ducting to provide a balanced defrost air-flow to the left and right windshield areas. Additionally, the top-center defrost air outlet 36 when opened tends to transmit undesirable HVAC blower noise directly to the occupants.
Thus, there is a need for an air distribution module for use in vehicle heating, ventilation, and air-conditioning systems that provides a more efficient air distribution within the vehicle without requiring additional complex ducting, and further delivers the correct air layer to the desired outlet.
In one aspect, the present invention includes an air distribution module for a vehicle heating, ventilation and air-conditioning system wherein the module receives a layered air-flow of an upper and a lower layer. The air distribution module includes a housing defining a central plenum and an air inlet at an upstream side thereof for receiving the layered air-flow of first and second layers. At least a first arcuate duct is coupled to the housing and defines an inner passage wherein the arcuate duct further includes an inlet coupled to a downstream side of the housing and in fluidic communication with the plenum. The duct further includes an inversion loop for inverting the air-flow layers and an outlet for discharging the air into the vehicle interior.
In another aspect of the present invention, an arcuate air duct for use in a vehicle heating, ventilation and air-conditioning system of the type that delivers layered air-flow to a distribution housing includes an inlet for coupling to a downstream side of the distribution housing and in fluidic communication with the housing for receiving a layered air-flow. The arcuate air duct further includes an inversion loop for inverting the air-flow layers and an outlet for delivering the air to the vehicle interior.
Yet another aspect of the present invention is a method of inverting and delivering a temperature layered air-flow from a vehicle heating, ventilation and air-conditioning system to the vehicle interior to selectively direct a desired temperature layer to a selected system outlet. The method includes the steps of providing a housing defining a plenum for receiving the layered air-flow at an upstream side; directing a first layer of cooler air to an upper portion of the housing plenum; and directing a second layer of warmer air to a lower portion of the housing plenum. Additional steps include affixing at least one arcuate duct in fluidic communication to a downstream side of the housing; providing an arcuate segment in the arcuate duct wherein the shape of the arcuate segment is such to invert the layers of the layered airflow; and finally directing the layered air-flow through the arcuate segment.
These and other features and advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.